1. Field of the Invention:
The present invention relates to a shield type tunneling apparatus for digging a tunnel through bedrock.
2. Description of the prior Art:
A conventional shield type tunneling machine comprise a shield body in a front portion of which is provided a hermetic cutter-head compartment in which are provided a plurality of disk-cutter units. In such conventional tunneling machine, the cutter-head compartment is rotatably driven by a driving unit of the machine so as to dig a tunnel through bedrock which is broken by the disk-cutter units. Such broken bedrock forms rock debris which is introduced into the cutter-head compartment through slits provided in a front portion of the cutter-head compartment, and then transported to a rear area of the shiled body through a suitable transporting means such as a screw conveyer and the like.
However, the conventional shield type tunneling machine provided with the hermetic cutter-head compartment lacks an effective means for discharging the rock debris from a front area of the shield body, which makes it substantially impossible to employ the conventional shield type tunneling machine in digging a tunnel through bedrock.